This invention relates to a linear tape storage system represented by DLT (Digital Linear Tape) or LTO (Linear Tape Open) and, in particular, to a reel hub lock releasing mechanism for use in the system.
A linear tape storage system of the type has been developed as a backup for a computer system. A variety of linear tape storage systems have heretofore been proposed. For example, a digital linear tape drive as the DLT is disclosed in U.S. Pat. No. 5,862,014.
The digital linear tape drive (hereinafter may simply be called the xe2x80x9cdrivexe2x80x9d or the xe2x80x9ctape drivexe2x80x9d) is adapted to receive a tape cartridge (hereinafter may simply be called the xe2x80x9ccartridgexe2x80x9d) having a single reel (supply reel). The digital linear tape drive includes a take-up reel in the interior thereof. When the tape cartridge is loaded in the drive, a magnetic tape is pulled out from the tape cartridge and is taken up by the take-up reel through a head guide assembly (HGA). The head guide assembly serves to guide to a magnetic head the magnetic tape (hereinafter may simply be called xe2x80x9ctapexe2x80x9d) pulled out from the tape cartridge. The magnetic head exchanges information to and from the tape.
The head guide assembly is also called a xe2x80x9ctape guide assemblyxe2x80x9d and is disclosed, for example, in U.S. Pat. No. 5,414,585. Besides, an example of the guide rollers is disclosed in Japanese Unexamined Patent Publication No. 2000-100025.
In general, a tape drive includes a generally rectangular having a common base, as stated in U.S. Pat. No. 5,793,574 by way of example. The base has two spindle motors (reel motors). The first spindle motor (reel motor) has a permanently mounted spool (take-up reel) permanently mounted to the base and dimensioned to accept a magnetic tape streaming at a relatively high speed. The second spindle motor (reel motor) is adapted to receive a removable tape cartridge. The removable tape cartridge is manually or automatically inserted into the drive via a slot formed on the housing of the drive. When the tape cartridge is inserted into the slot, the cartridge is engaged with the second spindle motor (reel motor). Prior to rotation of the first and the second spindle motors (reel motors), the tape cartridge is connected to the permanently mounted spool (take-up reel) by means of a mechanical buckling mechanism. A number of rollers (guide rollers) are located between the tape cartridge and the permanently mounted spool and guide the magnetic tape as it streams at a relatively high speed back and forth between the tape cartridge and the permanently mounted spool.
The digital linear tape drive of the above-mentioned structure requires a pulling device which allows the take-up reel to pull the tape from the supply reel. Such a pulling device is disclosed, for example, in International Publication No. WO86/07471. According to the disclosure in the publication, the take-up reel is provided with take-up leader means (first tape leader) coupled thereto. To the tape on the supply reel, supply leader means (second tape leader) is fixed. The first tape leader has a tab formed at its one end. The second tape leader has a locking hole. The tab is engaged with the locking hole.
Furthermore, a mechanism for joining the first tape leader to the second tape leader is required. Such a joining mechanism is disclosed, for example, in International Publication No. WO86/07295.
Japanese Unexamined Patent Publication No. 2000-100116 discloses xe2x80x9cStructure of Leader Tape Engaging Partxe2x80x9d capable of locking an end of a leader tape (second tape leader) to a tape end hooking part of the tape cartridge without requiring a tab protruding on a lateral side of the leader tape.
U.S. Pat. No. 5,857,634 discloses a lock system for preventing the rotation of the take-up reel of the tape drive when the tape cartridge is not inserted into the drive.
On the other hand, Japanese Unexamined Patent Publication No. 2000-149491 discloses an example of the tape cartridge to be loaded in the digital linear tape drive.
U.S. Pat. No. 6,241,171 discloses a xe2x80x9ctape drivexe2x80x9d in which a tape leader is urged from a tape cartridge to a take-up reel without using a buckling mechanism or a take-up leader.
The tape drive further includes a magnetic tape head actuator assembly. The magnetic tape head actuator assembly is located between the take-up spool and the tape cartridge along a tape path defined by a plurality of rollers. During operation, the magnetic tape streams back and forth between the take-up spool and the tape cartridge, coming into close proximity to the magnetic head actuator assembly while streaming along the defined tape path. An example of the magnetic head actuator assembly is disclosed in U.S. Pat. No. 5,793,574 mentioned above.
Meanwhile, as disclosed in Japanese Unexamined Patent Publication No. 2000-149491 mentioned above, the tape cartridge has a case, and a rotary reel or a supply reel which is rotatably accommodated in the case and around which a magnetic tape capable of carrying out recording/reproduction is wound. With such a tape cartridge, the rotational drive of the supply reel needs to be hindered in a state where the tape cartridge is not inserted in the slot of the tape drive. Otherwise, such a drawback might occur that, when the tape cartridge is being carried by way of example, the supply reel rotates in the tape cartridge, so the magnetic tape issues out of the tape cartridge. Therefore, the tape cartridge includes a reel hub lock mechanism for locking the reel hub of the supply reel. Such lock of the reel hub of the supply reel is called xe2x80x9creel hub lockxe2x80x9d in the pertinent field. That is, in the state where the tape cartridge is not inserted in the slot of the tape drive, it is held in a state where the reel hub of the supply reel is locked by the reel hub lock mechanism. A reel hub lock releasing mechanism includes a lock lever for making the reel hub lock releasable through an external manipulation.
On the other hand, the tape drive requires a mechanism for releasing the reel hub lock by manipulating the lock lever when or after the tape cartridge has been inserted into the slot. Such a mechanism is called xe2x80x9creel hub lock releasing mechanismxe2x80x9d. More specifically, the tape drive has a loading mechanism for bringing the supply reel into engagement with a supply reel motor after the tape cartridge has been inserted into the slot. The loading mechanism has a loading motor which is arranged on a chassis, and a ring cam which is driven by the loading motor. The ring cam is coaxial with the rotary shaft of the supply reel motor, it is rotatably arranged between the rear surface of the chassis and the supply reel motor, and it has a cam groove. The reel hub lock releasing mechanism has an engaging protrusion which engages with the cam groove of the ring cam. Besides, the reel hub lock releasing mechanism releases the reel hub lock by manipulating the lock lever in response to the turning of the ring cam when the tape cartridge has been inserted into the slot.
The lever manipulating protrusion of a release lever in the reel hub lock mechanism in the prior art engages with the lock lever through a square window which is provided so as to open near one side of the bottom of the tape cartridge. Such a tape cartridge has the release lever of the reel hub lock mechanism located on the drive side so as to prevent the tape from loosening during non-operation. Separately from the release lever, the tape cartridge includes a part for positioning itself.
In the prior-art reel hub lock mechanism, a large gap exists between the release lever and the window of the tape cartridge. In releasing the lock by the use of the release lever, therefore, the tape cartridge moves undesirably. This signifies the disadvantage that, unless the tape cartridge is positioned by the separate part, its position becomes unstable.
It is accordingly an object of this invention to provide that reel hub lock mechanism of a tape drive which can position a tape cartridge simultaneously with the release of reel hub lock without separately forming any positioning part.
According to an aspect of this invention, there is provided a reel hub lock releasing mechanism for a tape drive which has supply reel drive means for rotationally driving a supply reel included in a tape cartridge inserted into a slot and a loading mechanism connected to the supply reel drive means. The loading mechanism drives a ring cam after the tape cartridge has been inserted into the slot. The reel hub lock releasing mechanism makes a reel hub lock of the supply reel release so as to become rotatable when the tape cartridge has been inserted into the slot and comprises a lock lever disposed in the tape cartridge for making the reel hub lock releasable through an external manipulation and a seesaw type release lever arranged so as to be turnable with its central part as a fulcrum and including first and second flat members extending onto both sides from the fulcrum. The lock lever is manipulated in response to turning of the ring cam when the tape cartridge has been inserted into the slot. The first flat member has an engaging protrusion at its distal end, while the second flat member has at its distal end a lever manipulating protrusion which protrudes upwards in order to manipulate the lock lever. The tape cartridge is formed with a window for snugly inserting the lever manipulating protrusion. The lever manipulating protrusion abuts against the lock lever through the window, thereby to perform the lock releasing operation, and to simultaneously position the tape cartridge so that a position of the window in a direction of inserting the tape cartridge into the slot may become substantially equal to a position of the lever manipulating protrusion in the inserting direction.
According to another aspect of this invention, there is provided a tape drive which has a reel hub lock releasing mechanism including supply reel drive means for rotationally driving a supply reel included in a tape cartridge inserted into a slot and a loading mechanism connected to the supply reel drive means for driving a ring cam after the tape cartridge has been inserted into the slot. The reel hub lock releasing mechanism makes a reel hub lock of the supply reel release so as to become rotatable when the tape cartridge has been inserted into the slot and comprises a lock lever disposed in the tape cartridge for making the reel hub lock releasable through an external manipulation. The lock lever is manipulated in response to turning of the ring cam when the tape cartridge has been inserted into the slot.
In the aspect of this invention, the reel hub releasing mechanism comprises a seesaw type release lever arranged so as to be turnable with its central part as a fulcrum. The seesaw type relese lever includes first and second flat members extending onto both sides from the fulcrum. The first flat member has an engaging protrusion at its distal end, while the second flat member has at its distal end a lever manipulating protrusion which protrudes upwards in order to manipulate the lock lever. The tape cartridge is formed with a window for snugly inserting the lever manipulating protrusion. The lever manipulates protrusion abutting against the lock lever through the window, thereby to perform the lock releasing operation, and to simultaneously position the tape cartridge so that a position of the window in a direction of inserting the tape cartridge into the slot may become substantially equal to a position of the lever manipulating protrusion in the inserting direction.